This study is designed to explore the effect of dietary chromium supplementation on the metabolism of glucose in individuals with impaired glucose tolerance utilizing the hyperglycemic glucose clamp technique. The erythroid insulin radioreceptor is used to explore the possibility that chromium acts at the level of the receptor to promote glucose metabolism. Chromium levels in serum and urine in the fasting and hyperglycemic state are measured using electron absorption spectroscopy. In a separate phase of the study, associations among the variables age, sex, coronary heart disease, and fasting chromium levels are being examined.